Prime Minister Shinzo Abe has led Japan's first state-backed ceremony to mark the return of sovereignty in 1952 following its defeat in the second world war.

The move is being regarded warily by Beijing and South Korea which are suspicious of signs of rising nationalism in Japan and have long-standing territorial disputes with Tokyo.

Abe's Liberal Democratic Party (LDP) pledged during the campaign to make April 28 "Restoration of Sovereignty Day", to mark the day when the San Francisco peace treaty took effect, formally ending the war and the allied occupation.

"I wish to mark this day as a major milestone and make this a day on which we renew our hopes and our determination towards the future, reflecting on the path we have followed," Abe said at a ceremony yesterday, attended by about 400 people including Emperor Akihito and Empress Michiko.

"I believe we have an obligation to make Japan strong and robust and make it a country that the people of the world are able to depend on."

Akihito's father, Hirohito, was Japan's war-time leader, and made a historic broadcast announcing the terms of surrender to his people in 1945.

Prior to the event, the hawkish Abe said a ceremony would help younger Japanese "recognise" that the country regained independence following seven years of post-war occupation by US forces after its surrender.

Japanese conservatives have long criticised teachers as atoning for the country's imperialist past too much and failing to nurture patriotism in students.

The prime minister has devoted greater attention in recent weeks to a more hawkish stance on security and Japanese history ahead of a July upper house election that his ruling bloc needs to win to cement its grip on power.

Abe has also defended recent visits by more than 160 legislators to the Yasukuni shrine, which honours Japan's war dead but offends China and South Korea, where memories of Japanese occupation remain fresh.

Japan also has been embroiled with Beijing in a territorial dispute over uninhabited islets in the East China Sea, with Abe last week saying it would be "natural" to use force to repel any Chinese attempt to land on the islands.

Abe has also refused to clarify whether his cabinet endorses an apology for Japan's aggression before and during the second world war, issued by a previous government in 1995.

Additional reporting by Reuters

This article appeared in the South China Morning Post print edition as 'Sovereignty day' raises concerns